Adding an option for peers to negotiate the length of the QUIC

net/quic/quic_connection_test.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/quic_connection.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "net/base/net_errors.h"
 #include "net/quic/congestion_control/loss_detection_interface.h"
 #include "net/quic/congestion_control/receive_algorithm_interface.h"
 #include "net/quic/congestion_control/send_algorithm_interface.h"
 #include "net/quic/crypto/null_encrypter.h"
 #include "net/quic/crypto/quic_decrypter.h"
 #include "net/quic/crypto/quic_encrypter.h"
 #include "net/quic/quic_flags.h"
 #include "net/quic/quic_protocol.h"
 #include "net/quic/quic_utils.h"
 #include "net/quic/test_tools/mock_clock.h"
 #include "net/quic/test_tools/mock_random.h"
+#include "net/quic/test_tools/quic_config_peer.h"
 #include "net/quic/test_tools/quic_connection_peer.h"
 #include "net/quic/test_tools/quic_framer_peer.h"
 #include "net/quic/test_tools/quic_packet_creator_peer.h"
 #include "net/quic/test_tools/quic_sent_packet_manager_peer.h"
 #include "net/quic/test_tools/quic_test_utils.h"
 #include "net/quic/test_tools/simple_quic_framer.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using base::StringPiece;
@@ skipping 1475 matching lines @@
   // All packets carry version info till version is negotiated.
   QuicPacketCreator* creator =
       QuicConnectionPeer::GetPacketCreator(&connection_);
   size_t payload_length;
   // GetPacketLengthForOneStream() assumes a stream offset of 0 in determining
   // packet length. The size of the offset field in a stream frame is 0 for
   // offset 0, and 2 for non-zero offsets up through 64K. Increase
   // max_packet_length by 2 so that subsequent packets containing subsequent
   // stream frames with non-zero offets will fit within the packet length.
   size_t length = 2 + GetPacketLengthForOneStream(
-          connection_.version(), kIncludeVersion, PACKET_1BYTE_SEQUENCE_NUMBER,
+          connection_.version(), kIncludeVersion,
+          PACKET_8BYTE_CONNECTION_ID, PACKET_1BYTE_SEQUENCE_NUMBER,
           IN_FEC_GROUP, &payload_length);
   creator->set_max_packet_length(length);
 
   // Send 4 protected data packets, which should also trigger 1 FEC packet.
   EXPECT_CALL(*send_algorithm_, OnPacketSent(_, _, _, _, _)).Times(5);
   // The first stream frame will have 2 fewer overhead bytes than the other 3.
   const string payload(payload_length * 4 + 2, 'a');
   connection_.SendStreamDataWithStringWithFec(1, payload, 0, !kFin, nullptr);
   // Expect the FEC group to be closed after SendStreamDataWithString.
   EXPECT_FALSE(creator->IsFecGroupOpen());
   EXPECT_FALSE(creator->IsFecProtected());
 }
 
 TEST_P(QuicConnectionTest, FECQueueing) {
   // All packets carry version info till version is negotiated.
   size_t payload_length;
   QuicPacketCreator* creator =
       QuicConnectionPeer::GetPacketCreator(&connection_);
   size_t length = GetPacketLengthForOneStream(
-      connection_.version(), kIncludeVersion, PACKET_1BYTE_SEQUENCE_NUMBER,
+      connection_.version(), kIncludeVersion,
+      PACKET_8BYTE_CONNECTION_ID, PACKET_1BYTE_SEQUENCE_NUMBER,
       IN_FEC_GROUP, &payload_length);
   creator->set_max_packet_length(length);
   EXPECT_TRUE(creator->IsFecEnabled());
 
   EXPECT_EQ(0u, connection_.NumQueuedPackets());
   BlockOnNextWrite();
   const string payload(payload_length, 'a');
   connection_.SendStreamDataWithStringWithFec(1, payload, 0, !kFin, nullptr);
   EXPECT_FALSE(creator->IsFecGroupOpen());
   EXPECT_FALSE(creator->IsFecProtected());
@@ skipping 1351 matching lines @@
   EXPECT_CALL(*send_algorithm_, OnPacketSent(_, _, 1, _, _)).Times(0);
   connection_.SendPacket(
       ENCRYPTION_NONE, 1, packet, kTestEntropyHash, HAS_RETRANSMITTABLE_DATA);
   EXPECT_EQ(1u, connection_.NumQueuedPackets());
 }
 
 TEST_P(QuicConnectionTest, TestQueueLimitsOnSendStreamData) {
   // All packets carry version info till version is negotiated.
   size_t payload_length;
   size_t length = GetPacketLengthForOneStream(
-      connection_.version(), kIncludeVersion, PACKET_1BYTE_SEQUENCE_NUMBER,
+      connection_.version(), kIncludeVersion,
+      PACKET_8BYTE_CONNECTION_ID, PACKET_1BYTE_SEQUENCE_NUMBER,
       NOT_IN_FEC_GROUP, &payload_length);
   QuicConnectionPeer::GetPacketCreator(&connection_)->set_max_packet_length(
       length);
 
   // Queue the first packet.
   EXPECT_CALL(*send_algorithm_,
               TimeUntilSend(_, _, _)).WillOnce(
                   testing::Return(QuicTime::Delta::FromMicroseconds(10)));
   const string payload(payload_length, 'a');
   EXPECT_EQ(0u, connection_.SendStreamDataWithString(3, payload, 0, !kFin,
                                                      nullptr).bytes_consumed);
   EXPECT_EQ(0u, connection_.NumQueuedPackets());
 }
 
 TEST_P(QuicConnectionTest, LoopThroughSendingPackets) {
   // All packets carry version info till version is negotiated.
   size_t payload_length;
   // GetPacketLengthForOneStream() assumes a stream offset of 0 in determining
   // packet length. The size of the offset field in a stream frame is 0 for
   // offset 0, and 2 for non-zero offsets up through 16K. Increase
   // max_packet_length by 2 so that subsequent packets containing subsequent
   // stream frames with non-zero offets will fit within the packet length.
   size_t length = 2 + GetPacketLengthForOneStream(
-          connection_.version(), kIncludeVersion, PACKET_1BYTE_SEQUENCE_NUMBER,
+          connection_.version(), kIncludeVersion,
+          PACKET_8BYTE_CONNECTION_ID, PACKET_1BYTE_SEQUENCE_NUMBER,
           NOT_IN_FEC_GROUP, &payload_length);
   QuicConnectionPeer::GetPacketCreator(&connection_)->set_max_packet_length(
       length);
 
   // Queue the first packet.
   EXPECT_CALL(*send_algorithm_, OnPacketSent(_, _, _, _, _)).Times(7);
   // The first stream frame will have 2 fewer overhead bytes than the other six.
   const string payload(payload_length * 7 + 2, 'a');
   EXPECT_EQ(payload.size(),
             connection_.SendStreamDataWithString(1, payload, 0, !kFin, nullptr)
                 .bytes_consumed);
 }
 
+TEST_P(QuicConnectionTest, LoopThroughSendingPacketsWithTruncation) {
+  ValueRestore<bool> old_flag(&FLAGS_allow_truncated_connection_ids_for_quic,
+                              true);
+
+  // Set up a larger payload than will fit in one packet.
+  const string payload(connection_.max_packet_length(), 'a');
+  EXPECT_CALL(*send_algorithm_, SetFromConfig(_, _)).Times(AnyNumber());
+
+  // Now send some packets with no truncation.
+  EXPECT_CALL(*send_algorithm_, OnPacketSent(_, _, _, _, _)).Times(2);
+  EXPECT_EQ(payload.size(),
+            connection_.SendStreamDataWithString(
+                3, payload, 0, !kFin, nullptr).bytes_consumed);
+  // Track the size of the second packet here.  The overhead will be the largest
+  // we see in this test, due to the non-truncated CID.
+  size_t non_truncated_packet_size = writer_->last_packet_size();
+
+  // Change to a 4 byte CID.
+  QuicConfig config;
+  QuicConfigPeer::SetReceivedBytesForConnectionId(&config, 4);
+  connection_.SetFromConfig(config);
+  EXPECT_CALL(*send_algorithm_, OnPacketSent(_, _, _, _, _)).Times(2);
+  EXPECT_EQ(payload.size(),
+            connection_.SendStreamDataWithString(
+                3, payload, 0, !kFin, nullptr).bytes_consumed);
+  // Verify that we have 8 fewer bytes than in the non-truncated case.  The
+  // first packet got 4 bytes of extra payload due to the truncation, and the
+  // headers here are also 4 byte smaller.
+  EXPECT_EQ(non_truncated_packet_size, writer_->last_packet_size() + 8);
+
+
+  // Change to a 1 byte CID.
+  QuicConfigPeer::SetReceivedBytesForConnectionId(&config, 1);
+  connection_.SetFromConfig(config);
+  EXPECT_CALL(*send_algorithm_, OnPacketSent(_, _, _, _, _)).Times(2);
+  EXPECT_EQ(payload.size(),
+            connection_.SendStreamDataWithString(
+                3, payload, 0, !kFin, nullptr).bytes_consumed);
+  // Just like above, we save 7 bytes on payload, and 7 on truncation.
+  EXPECT_EQ(non_truncated_packet_size, writer_->last_packet_size() + 7 * 2);
+
+  // Change to a 0 byte CID.
+  QuicConfigPeer::SetReceivedBytesForConnectionId(&config, 0);
+  connection_.SetFromConfig(config);
+  EXPECT_CALL(*send_algorithm_, OnPacketSent(_, _, _, _, _)).Times(2);
+  EXPECT_EQ(payload.size(),
+            connection_.SendStreamDataWithString(
+                3, payload, 0, !kFin, nullptr).bytes_consumed);
+  // Just like above, we save 8 bytes on payload, and 8 on truncation.
+  EXPECT_EQ(non_truncated_packet_size, writer_->last_packet_size() + 8 * 2);
+}
+
 TEST_P(QuicConnectionTest, SendDelayedAck) {
   QuicTime ack_time = clock_.ApproximateNow().Add(DefaultDelayedAckTime());
   EXPECT_CALL(visitor_, OnSuccessfulVersionNegotiation(_));
   EXPECT_FALSE(connection_.GetAckAlarm()->IsSet());
   const uint8 tag = 0x07;
   connection_.SetDecrypter(new StrictTaggingDecrypter(tag),
                            ENCRYPTION_INITIAL);
   framer_.SetEncrypter(ENCRYPTION_INITIAL, new TaggingEncrypter(tag));
   // Process a packet from the non-crypto stream.
   frame1_.stream_id = 3;
@@ skipping 1050 matching lines @@
   QuicBlockedFrame blocked;
   blocked.stream_id = 3;
   EXPECT_CALL(visitor_, OnBlockedFrames(_));
   ProcessFramePacket(QuicFrame(&blocked));
   EXPECT_TRUE(ack_alarm->IsSet());
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net